New Species of Fossil Plants. 423 



natifid ; pinnae pinnatifid above ; pinnules lanceolate, one 

 inch long, enlarged at the base; united together and decur- 

 rent above, distinct below ; deeply undulate on the margins ; 

 secondary nerves obsolete, very slender and oblique ; bifur- 

 cate, slightly arched. 



54. Alethopteris serrula (spec. nov.). Frond pinnati- 

 fid, large ; pinnules alternate sessile, perpendicular to the 

 rachis or inclined backwards, straight, linear, four inches long 

 and more, pinnately lobed ; lobes alternate, two to three times 

 toothed, sometimes entire and obtuse ; secondary nerves 

 once or twice forking. 



55. Alethopteris l^jvis (spec, nov ?). Diners from Ale- 

 thopteris nervosa only by its shorter pinnules and entirely 

 smooth surface, without any trace of nerves ; (an species 

 propria.) 



Genus CALLIPTEEIS. Brongt. 



56. Callipteris Sullivantii (spec. nov.). Frond bipin- 

 nate ; pinnae lanceolate ; pinnules alternate, oblique, obovate 

 or oblong, nearly contiguous, slightly decurrent, and united 

 together near the base by a slightly obtuse sinus ; medial nerve 

 broad, canaliculate, disappearing at the middle ; secondary 

 nerves arched, slender, close, many times forking. 



Genus PECOPTERIS. Broogt. 



57. Pecopteris distans (spec. nov.). Has the nervation 

 of Pecopteris polymorpha ; diners from it by its distant pin- 

 nules, oval, lanceolate, narrowed at the base, and attached to 

 the rachis only by the thickened medial nerve. 



58. Pecopteris velutina (spec. nov.). Frond bipin- 

 natifid ; lower pinnae perpendicular to the rachis, pinnate, 

 broadly linear-lanceolate ; 1£ to 2 inches long; pinnules dis- 

 tinct, slightly contracted in the middle, and enlarged above 

 the base, sessile, united only at the summit of the pinnae ; 

 upper pinnae simple, pinnately undulate, lobed, or entire; 



